Chromium enables insulin (which controls blood sugar levels) to function and helps in the processing (metabolism) and storage of carbohydrates, protein, and fat. Only a small amount of the chromium in food is absorbed. Chromium is absorbed better when eaten with foods that contain vitamin C and niacin. Supplements do not enhance muscle size or strength in men.
Deficiency: Chromium deficiency is rare in developed countries. Children who are undernourished may have chromium deficiency and grow poorly. Several conditions can reduce the amount of chromium in the body:
• A diet high in simple sugars, which causes more chromium to be excreted in urine
• Infections
• Exercise if strenuous
• Pregnancy and breastfeeding
• Injuries
• Intravenous feeding (total parenteral nutrition) for a long time.
Symptoms may include weight loss, confusion, impaired coordination, and a reduced response to sugar (glucose) in blood, increasing the risk of diabetes. Treatment may involve chromium supplements.
Excess: Small amounts of chromium taken by mouth are not harmful. In the workplace, people may be exposed to a different, toxic form of chromium. This form results from industrial pollution. This form may irritate the skin, cartilage of the nose, lungs, and digestive tract and may cause lung cancer.
Resource: Merck Manual Home Edition